how can i use _MainTex in urp 3dLit shader instead of _BaseMap?

Unity Engine
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1

hello guys,I’m now making a 2d game in 3d worlds,I have to use 3d lit shader(like pbr master in shader graph) because i need to use 3d light,then I need to use SpriteRender for some reason,so I just want when i m choosing a 3dlit material for the spriteRender, the _baseMap will automaticly change to spriteRender.sprite.
In my test,when i using the standard material or 2d lit shader, this will be happen because they are using _MainTex for texture,but in 3d lit shader or 3d sample lit shader i see the mainTex is obsoluted.

I m sorry to ask this because i know almost nothing about shader program,so please help me to solve this thanks.

2

for now ,i have to create materials for each Obj which have spriterender,